Recently,　single-particle　tracking　has　emerged　as　a　key　tool　for　revealing　transport　and　interactions　at　the　nanoscale.　Traditional　fluorescence　methods　are　limited　by　photobleaching,　while　interferometric　scattering　requires　stringent　optical　stability.　This　study　demonstrates　highly　inclined　and　laminated　optical　sheet　(HILO)　microscopy　enhanced　by　localized　surface　plasmon　resonance　(LSPR)　of　gold　nanoparticles　as　a　simple　alternative　on　a　commercial　inverted　microscope.　The　oblique　illumination　suppresses　an　out-of-focus　background　while　LSPR　selectively　amplifies　elastic　scattering,　delivering　order-of-magnitude　gains　in　single-particle　signal-to-noise　without　fluorescent　labels.　Rapid　image　sequences　are　processed　with　TrackMate-MATLAB　to　generate　thousands　of　Brownian　trajectories　in　each　acquisition.　Ensemble　mean-square-displacement　analysis　yields　the　measured　diffusion　coefficients　that　match　Stokes-Einstein　predictions　to　within　2%　and　exhibit　coefficients　of　variation　below　3.5%　across　independent　replicates.　The　optical　adjustment　requires　only　rotation　of　the　excitation　beam,　making　the　platform　low-cost,　high-throughput,　and　readily　scalable　for　interrogating　nanoparticle　dynamics　in　physiological　environments.　It　also　lays　the　foundation　for　integrating　chemical　fingerprinting　modalities　such　as　surface-enhanced　Raman　scattering　(SERS)　at　the　single-particle　level　in　the　future.　©　2025　Optica　Publishing　Group　under　the　terms　of　the　Optica　Open　Access　Publishing　Agreement